1. Field of the Invention
The present invention relates to a sheet feeding device suited for mounting on a recording apparatus, a reading apparatus, or an image reading and recording apparatus.
2. Description of the Related Art
Feeding devices are widely used as a unit that feeds a sheet to an image forming portion or a reading portion in apparatuses functioning as printers, copiers, and/or facsimile machines. A sheet feeding device is configured to separate one sheet from a sheet bundle of recording media, such as paper, cloth, plastic sheets, or transparencies, (hereinafter referred to as recording sheets) or reading media (hereinafter referred to as documents) and to feed the separated sheet to a processing portion, such as an image forming portion or a reading portion.
There is an image reading and recording apparatus that reduces the number of parts by using a feeding mechanism shared for recording sheets and documents to miniaturize the size of the apparatus and cut costs. In addition, U.S. patent application Publication No. 2005-0286942 discloses an image reading and recording apparatus that aims to reduce the size and costs by using a shared feeding device to separate one sheet from the other documents or recording sheets and to feed the separated sheet and a shared conveying mechanism to convey the fed sheet.
However, in the image reading and recording apparatus described in this patent document, a document supporting portion for supporting documents is disposed above a recording-sheet stacking portion for supporting recording sheets. Thus, it is necessary to set a bundle of documents on the document supporting portion such that the leading end of the documents is positioned adjacent to the peripheral surfaces of the feeding roller. For this reason, when a document curled upward is set or a document is roughly set by a user, the leading end of the document may come into contact with the feeding roller. This may cause an unstable set state of the document, thus resulting in a reduction in the separating and feeding abilities.
In the image reading and recording apparatus described in this patent document, the document supporting portion is disposed above the recording-sheet stacking portion. Thus, the lower surface of a document can be held and guided, whereas the upper surface of the document cannot be guided. In this arrangement, a space above the set documents is large. Thus, in the case of a thin document (e.g., a slip), the leading end of the thin document may be bent by its own weight and the bent document may be set. In this case, the separating and feeding abilities to transport the document may be reduced. The separating ability may also be reduced by undesirable bending of the leading end of a protruding document while being returned to a support portion by a return lever.